The present invention relates generally to nanoparticles, and more particularly to thermo-sensitive nanoparticles and magnetic nanoparticles. Thermo-sensitive or temperature sensitive polymer nanoparticle have applications in various fields, especially in biotechnology and medicine, including cell culture, tissue engineering, wound healing, and drug delivery systems. For instance, temperature sensitive nanoparticles have been developed as controlled release drug delivery carriers used in cancer treatment and gene therapy. A major advantage of the temperature sensitive nanoparticles as a drug delivery system is their phase change due to temperature. Temperature sensitive polymers undergo a reversible phase transition at a lower critical solution temperature (“LCST”), where the hydrogel hydrophobically collapses and squeezes water out in an entropically favored fashion. A reversible swelling and shrinking behavior based on this phenomenon has been used as a means to control loading and releasing of various therapeutic agents. For example, drugs can be loaded in these nanoparticles at temperatures below the LCST.
A variety of polymers have been used to produce the temperature sensitive nanoparticles as drug delivery systems, although it is difficult to incorporate other molecules such as antibodies and proteins onto temperature sensitive nanoparticles to increase their targeted capabilities. With these nanoparticles, conjugation is possible by performing additional synthetic steps which would introduce impurities altering the LCST significantly. Consequently, there is a need to introduce another monomer to the copolymer of N-isopropylacrylamide (NIPA) and acrylamide (AAm) to functionalize the nanoparticles without changing its LCST dramatically.
Polymeric magnetic nanoparticles (PMNPs) have been developed over many decades for use in several applications such as cell separation, DNA/RNA purification, immunoassays, contrast agents in magnetic resonance imaging (MRI), magnetic targeted drug carriers, tissue engineering, and hyperthermia treatments for cancer. These nanoparticles contain core-shell structures with the core made of magnetic materials and the shell made of either natural or synthetic polymers. Natural polymers such as albumin, cellulose, pullulan, and chitosan, as well as synthetic polymers like polystyrene, poly acrylamide, and poly(L-lactic-co-glycolic) acid have been used to coat magnetic nanoparticles; however the coatings are ineffective and not biocompatible. The embodiments disclosed herein solve these problems as well as others.